In machining such as cutting, grinding, etc., using a machine tool, the machining is carried out while supplying coolant (cutting oil, grinding oil, air, etc.) to a cutting zone for lubrication, cooling, chip removal and preventing welding of chips. The coolant application device is used as a device for applying this coolant to the cutting zone. In the coolant application device, the coolant is precisely jetted to the cutting zone by using a motor to drive a nozzle for spouting the coolant, and by adjusting the position or the angle of the nozzle according to the tool change or the progress of machining process. For example, a well-known coolant application device is described in Patent Publication 1.
Patent Publication 1 is Japanese Unexamined Patent Application Publication No. 2012-228739.